title: Exercise ankle brachial index adds important prognostic information on long-term out-come only in patients with a normal resting ankle brachial index.
abstract: BACKGROUND
  The clinical value of exercise ankle brachial index (ABI) is still unclear, especially in patients with normal resting ABI.
  
  
  METHODS
  2164 patients performed a single-stage treadmill exercise test to diagnose or evaluate PAD. The population was divided into two groups: a normal resting ABI (resting ABI≥0.90) and PAD (resting ABI<0.90). Patients with a normal resting ABI were divided into 4 exercise ABI groups: exercise ABI<0.90, 0.90-0.99, 1.00-1.09 and 1.10-1.29 (reference).
  
  
  RESULTS
  Mean follow-up was 5 years. Exercise ABI added significant prognostic information on all cause long-term mortality only in patients with normal resting ABI (p-value 0.014, HR 0.99 95% CI (0.98-0.99)), not in patients with PAD. Fifty years or older (OR 2.93 95% CI (1.65-5.20)) and resting systolic blood pressure>140 mmHg (OR 2.18 95% CI (1.35-3.55)) were associated with an abnormal exercise ABI in patients with a normal resting ABI. Mortality rate increased when the exercise ABI became worse (p trend 0.0001) with a 2.5-fold increase mortality risk in patients with a normal resting ABI but exercise ABI <0.90 (HR 2.56, 95% CI (1.11-5.91)).
  
  
  CONCLUSIONS
  In patients with a normal resting ABI, treadmill exercise ABI added important prognostic information on long-term mortality. Based on our results we recommend that at least all patients suspected for PAD, with a resting ABI≥0.90, who are 50 years or older and having hypertension should undergo treadmill exercise testing.
authors.affiliation: Department of Anesthesiology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Inge I
authors.initials: II
authors.lastname: de Liefde
authors.forename: Jan
authors.initials: J
authors.lastname: Klein
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Hence J M
authors.initials: HJ
authors.lastname: Verhagen
authors.forename: Ron T
authors.initials: RT
authors.lastname: van Domburg
authors.forename: Don
authors.initials: D
authors.lastname: Poldermans
mesh_terms: D000368:Aged; D000842:Ankle / Q000503:physiopathology*; D055109:Ankle Brachial Index; D001158:Arteries / Q000473:pathology; D001794:Blood Pressure; D015992:Body Mass Index; D002309:Cardiology / Q000379:methods; D005080:Exercise Test; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000150:complications / Q000503:physiopathology*; D011379:Prognosis; D012307:Risk Factors; D016896:Treatment Outcome